Utility meters, including mechanical, electromechanical, and solid state meters, are well known and have been used for many years to measure the consumption of resources such as water, gas and electricity. Water meters, for example, generate data indicative of the consumption of water, where such data is used for billing purposes. Initially, utility meters were mechanical devices. As electronic technology advanced, such technology became smaller and less expensive, and thus, more suitable for use in the highly competitive and cost sensitive utility meter market. As such, the use of electromechanical (hybrid meters) and electronic meters has become more common. Indeed, most modern electricity meters, for example, are electronic meters (static meters).
Traditionally, meter reading personnel would periodically travel to each utility meter installation site and inspect a meter installation and manually record consumption data. The customer would then receive a bill based on such collected data. Today, increasing numbers of utilities are installing the most advanced reading technologies available. Such systems typically included a transmitter/transceiver associated with the utility meter for transmitting utility meter data to a remote location thereby offering improved data accuracy at the lowest meter reading cost available while eliminating the need for meter access (which is particularly useful for hazardous reading environments).
Notably, AMR systems used by water utilities include devices installed at the water meter configured for transmitting a data signal. Such devices are particularly sensitive to power consumption as most water meter installations are battery operated. As a result, such systems typically employ power saving schemes such as a drive-by/walk-by system.
For walk-by and drive-by AMR systems, a transmitter is associated with a utility meter and configured to wake up and transmit consumption data at a predefined time for a predefined duration in time (e.g. transmitter wakes up every day at 4:00 pm and transmits a 10 ms data burst every 10 seconds until 6:00 pm and then goes back into sleep mode). During the active period of the transmitter (between 4:00 pm and 6:00 pm for the above example) a utility representative either walks-by or drives-by the utility meter to receive the transmitted consumption data signal. Such a one-way system was disclosed in commonly owned U.S. patent application Ser. No. 10/989,811 filed on Nov. 16, 2004.
For yet another walk-by/drive-by AMR system, a transceiver replaces the transmitter. For this AMR system a simple receiver is configured for receiving a wake-up signal to be transmitted by utility personnel as he drives-by/walks-by a meter installation. When a wake-up signal is received, the AMR system's transmitter is activated and starts transmitting a data signal. Such a one-way system was disclosed in commonly owned U.S. patent application Ser. No. 10/989,811 filed on Nov. 16, 2004.
Conversely, a fixed network system eliminates the need to drive-by/walk-by a utility meter. For such a system, either the transmitter system (a) tracks the passage of time and transmits a data signal according to a predefined schedule or (b) the transmitter system includes a transceiver that listens for a wakeup signal. When a wake-up signal is received, the transmitter activates and transmits a consumption data signal to a remote location. Such a two-way system was disclosed in commonly owned U.S. Pat. No. 7,283,063 (application filed Jul. 7, 2005).
Prior to the development of the above described AMR transmitters there was a problem with prior art systems in that prior art drive-by/walk-by and Fixed network AMR systems were not compatible with each other. Restated, prior art drive-by/walk-by transmitters were not configured to operate in fixed network systems and vice-versa. For example, a typical drive-by/walk-by system transmitter may transmit a 0.08 Watt data signal while a typical fixed network transmitter may operate at up to 1.0 watts (or perhaps more in some frequency bands). Additionally, it should be appreciated that for a two way communication system, if a first transceiver (T1) transmits an X-watt signal to a second transceiver (T2), transceiver T2 should transmit an X-watt response signal (to minimize the risk of saturating the receiver). To use an analogy, if person A whispers to person B, person B should whisper back to person A, not shout back.
Such incapability between walk-by/drive-by/fixed network systems presents a problem to water utilities. The technology that provides the above described advantages is not free and utilities must be careful to select the best AMR system for their needs. Additionally, while a fixed network system may clearly the best technical solution for a particular utility; such utility may not have the funds to install a fixed network solution. Thus, such a utility may simply purchase a system it can afford such as a less expensive walk-by/drive-by system. When the above described utility decides to upgrade to a fixed network solution as funds become available, it must replace the drive-by transmitters with RF systems suitable for a fixed network. Such an upgrade process is clearly a waste of resources as perfectly good transmitters are scrapped.
What is needed is an AMR device configured to be associated with a water utility meter that may be configurable to operate in one of a plurality of modes (such as a walk-by, drive-by and a Fixed Network mode) that includes auto-calibration routines to configure the network. With such an AMR device, a water utility may first implement a walk-by/drive-by AMR system and then upgrade to a fixed network solution at minimal costs. Additionally, there is a need for a self calibrating system that can determine the optimum transmitter power level to avoid having one transmitter “shout” when it could “whisper” thereby lowering power consumption while improving communication integrity.
Yet another problem with transmitters associated with water meters is the power source. All know prior art transmitters associated with a water meter include a battery. While most prior art utility meters powered by a battery use batteries with a life span of 5 or more years, the cost of ownership of a transmitter with a battery compared to a transmitter with no battery is significantly greater. In fact, perhaps the most common question a potential owner of a utility meter will ask is: “how long will the batteries last?” In various embodiments of the disclosed invention, the system includes transmitters that scavenge electromagnetic energy from the environment that is stored in electronic components such as capacitors and perhaps batteries. Restated, embodiments of the current invention include a battery free transmitter design.